State begins monitoring mosquitoes for disease

The state today has begun monitoring mosquitoes for viruses that can cause human illnesses including West Nile virus and eastern equine encephalitis virus.

The Mosquito Management Program, coordinated by the Connecticut Agricultural Experiment Station, began its monitoring on June 2. Test results to date are negative, the program said in a news release today.

The mosquito trapping and testing program also released surveillance results from the 2013 season, including the first confirmed human case of eastern equine encephalitis in a Connecticut resident.

In April, the Centers for Disease Control and Prevention confirmed that an adult resident of eastern Connecticut who had been hospitalized with encephalitis and had died last fall, was positive for EEE. The resident had been tested for WNV, but had not been tested for EEE before death. Further testing at a local hospital led to the post-mortem diagnosis of EEE infection.

“While rare, EEE is serious and underscores the importance of taking personal precautions to avoid mosquito bites,” Public Health Commissioner Dr. Jewel Mullen said. “The presence of this virus in Connecticut should also remind clinicians to include EEE, along with WNV, among their possible diagnoses so that appropriate tests can be done.”

Mullen said the state public health department is preparing an advisory to Connecticut clinicians regarding the current epidemiology of EEE and WNV, as well as testing options for diagnosing mosquito-borne diseases.

Last season there was significant EEE virus circulation in eastern Connecticut, including infected mosquitoes, a horse, and pheasant flocks. Mosquitoes with EEE virus were identified in five Connecticut towns: Haddam, Hampton, North Stonington, Plainfield and Voluntown. A horse stabled in Griswold died from EEE-associated illness during the second week of September. In early to mid-September, pheasants in a farm flock in Killingly and a flock in Sprague died from EEE infections.

The numbers and types of mosquitoes with EEE identified in the Pachaug State Forest in Voluntown last year prompted the Department of Energy and Environmental Protection to close temporarilypart of the forest to recreational activities and to conduct ultra-low volume ground spraying to reduce the number of mosquitoes.

Last season, the experiment station identified WNV-positive mosquitoes at trap sites in 22 towns, including Groton, Plainfield, Voluntown and Waterford. Four Connecticut residents from the towns of Stamford, Stratford, and Bridgeport were diagnosed with WNV-associated illnesses. There were no fatalities.

The mosquito management program is an effort of the experiment station, the state department of energy and environmental protection, agriculture, public health and the University of Connecticut Department of Pathobiology. The experiment station maintains a network of 91 mosquito-trapping stations in 72 municipalities throughout the state.

The locations of mosquito pools that test positive for WNV and EEE, as well as human cases of these illnesses, are posted on the state's website.